Synthesis of fatty acid methyl ester and fatty acid ethyl ester

Abstract

In the present invention a new synthesis method for fatty acid methyl ester and fatty acid ethyl ester is provided. More specifically, a fatty oil composition obtained from dried insects by mechanical treatment is reacted with aliphatic alcohols in the presence of alkali metal alkoxide salts such as methoxide or ethoxide to obtain fatty acid methyl ester (FAME) or fatty acid ethyl ester (FAEE).

Description

[0001] Synthesis of fatty acid methyl ester and fatty acid ethyl ester

[0002] Field of the invention

[0003] In the present invention a new synthesis method for fatty acid methyl ester and fatty acid ethyl ester is provided. More specifically, a fatty oil composition obtained from dried insects by mechanical treatment is reacted with alkali metal alkoxide salts such as methoxide or ethoxide to obtain fatty acid methyl ester (FAME) or fatty acid ethyl ester (FAEE).

[0004] Background

[0005] Fatty acid methyl ester (FAME) is also known as biodiesel. Biodiesel is a renewable and environmentally friendly liquid fuel. However, the feedstock, predominantly crop oil, is a valuable resource mainly used for food and feed which, to certain extend, limits some larger scale chemical applications of biodiesel. Development of non-food feedstocks or feedstocks that can be used for food and biodiesel applications in parallel are therefore needed to fully utilize biodiesel’s potential.

[0006] Production cost is the main obstacle preventing biodiesel from being used as a primary fuel. Cost analysis shows that 75% of biodiesel cost is derived from the feedstock, primarily crop oil such as soybean oil, rapeseed oil and sunflower oil. In addition to its economic constraints, crop oil is a limited food resource. To overcome these challenges, non-food feedstocks such as Jatropha curcas, Chinese tallow and microalgae are being used for biodiesel production. However, these alternative feedstocks face their own challenges, such as, long lifecycle, competing for crop land, and competing for limited water resources.

[0007] Furthermore, organic wastes such as animal wastes, residential wastes (e.g., household), commercial wastes (e.g., from stores, markets, shops, hotels, etc.), and institutional wastes (e.g., schools, hospitals, etc.) are generated in large quantities. These organic wastes can be used to raise high fat-containing insects, which can subsequently be utilized for biodiesel production.

[0008] One insect species with particular interest in this field is the black soldier fly (Hermetia illucens) (BSF). The BSFL larva possesses high contents of both protein and fatty acids. Whereas the protein can be used in the food and feed industry, for example to prepare dog food, the fatty acid may be further converted to biodiesel.

[0009] Thus, there is an interested in a preparation method for fatty acid methyl ester and fatty acid ethyl ester starting from insect feedstock that allows the subsequent processing of the protein fraction and that can be used in large-scale industrial applications. In this context, Mohan et al. (Mohan, K. et al., Science of the Total Environment 859 (2023) 160235) disclose different possibilities to prepare biodiesel from black soldier fly. However, all of these methods involve a chemical extraction step to separate the fatty acids and the other parts of the larva, such as proteins. Usually, the extraction involves n-hexane or petroleum ether. The use of such chemicals interferes with the further processing of the protein fraction. Moreover, Mohan et al. highlight the two-step process for the biodiesel production from BSF larvae including an acid-catalyzed esterification and an alkaline-catalyzed transesterification.

[0010] Along this line, Li et al. (Li, Q. et al., Fuel 90 (2011) 1545-1548) disclose biodiesel production from black soldier fly larvae (BSFL) involving a step of chemical extraction using petroleum ether and the two-step process of acid-catalyzed esterification and alkaline-catalyzed transesterification to convert the fatty acid to FAME.

[0011] On the other hand, some literature discloses the conversion of fatty acids into fatty acid methyl ester for analytical purposes. However, these methods involve significantly smaller amounts of reactants, and it is not clear if such reactions can be up scaled, in particular for reactions involving fatty acids derived from insects without using any chemical extraction steps. For example, Christie (Christie, W.W. Journal of Lipid Research Volume 23, pages 1072-1075, 1982) discloses the conversion of 1 -10 mg of glycerolipids into FAME for gas-liquid chromatographic (GLC) analysis. Other analytical studies of fatty acids describe FAME preparation involving boron trifluoride (BF3) solved in methanol. However, BF3 is a highly toxic gas and should thus be avoided for large-scale industrial applications.

[0012] Therefore, there is a need in the art for methods to prepare fatty acid methyl ester and fatty acid ethyl ester starting from insect feedstock that allow further processing of the protein fraction of the insect larvae and that can be up scaled for industrial applications.

[0013] Surprisingly, the present inventors found that a fatty oil composition that has been obtained from insect larvae solely by mechanical treatment, such as cold pressing, and that has not been exposed to a further chemical extraction, can directly be used in a transesterification reaction using alkali metal alkoxide salts such as methoxide or ethoxide. The resulting products are glycerol and fatty acid methyl ester (FAME) or fatty acid ethyl ester (FAEE). Such reactions are one-step reactions that can be up scaled for industrial applications. Additionally, the mild treatment of the larvae will allow to use the protein fraction in diverse applications including the use in the food and feed industry.

[0014] Brief summary of the invention

[0015] In a first aspect, the present invention is directed to a method for preparation, and preferably processing, of fatty acid methyl ester (FAME) or fatty acid ethyl ester (FAEE) comprising: i) obtaining a fatty oil composition by mechanical treatment of dried insects, with the proviso that the treatment does not include a chemical extraction step; iia) reacting the fatty oil composition of step i) in methanol comprising at least 0.5 % by weight of sodium methoxide, potassium methoxide or lithium methoxide for at least 30 minutes at at least 60 °C under N2 atmosphere with a pressure of at least 2.5 bar, in order to obtain the fatty acid methyl ester (FAME), or iib) reacting the fatty oil composition of step i) in ethanol comprising at least 0.5 % by weight of sodium ethoxide, potassium ethoxide or lithium ethoxide for at least 30 minutes at at least 60 °C under N2 atmosphere with a pressure of at least 2.5 bar, in order to obtain the fatty acid ethyl ester (FAEE).

[0016] In preferred embodiments, the fatty oil composition has a protein content of at least 0.1 %, preferably at least 0.25% and more preferably at least 1 % in relation to the total weight of said composition.

[0017] In other preferred embodiments, the amount of fatty oil composition reacted in step iia) or iib) is at least 10 gram, preferably at least 20 gram and more preferably at least 25 gram.

[0018] In still further preferred embodiments, the mechanical treatment is pressing and more preferably cold pressing.

[0019] In preferred embodiments, the alkali metal methoxide is sodium methoxide.

[0020] In other preferred embodiments, in the reaction of step iia) or iib)

[0021] - the reaction time is between 20 to 120 minutes and preferably between 30 to 90 minutes and more preferably between 45 to 75 minutes;

[0022] - the reaction temperature is between 65 to 100 °C, preferably between 75 to 95 °C and more preferably between 80 to 90 °C;

[0023] - the methanol comprises 0.25 to 2 % and preferably 0.5 to 1 .5 % by weight of the alkali metal methoxide;

[0024] - the ethanol comprises 0.25 to 2 % and preferably 0.5 to 1.5 % by weight of the alkali metal ethoxide; and / or

[0025] - the N2 partial pressure is between 2 to 10 bar, preferably between 3.5 to 7.5 bar and more preferably between 4 to 5 bar.

[0026] Further, in preferred embodiments, the reaction of step iia) or iib) does not include addition of boron trifluoride.

[0027] In still further embodiments, the insect

[0028] - was dried at its larva stage; and / or

[0029] - is a holometabolic insect.

[0030] In preferred embodiments, the insect isfrom the genus of Diptera, preferably Brachycera and is more preferably Hermetia illucens. In other preferred embodiments, the fatty acid methyl ester (FAME) or fatty acid ethyl ester (FAEE) is purified by phase separation and / or distillation.

[0031] In still other preferred embodiments, the fatty acid methyl ester (FAME) or fatty acid ethyl ester (FAEE) is processed into fatty alcohol, fatty amine, fatty amide, fatty acid carboxylate, fatty methyl ketone, dimer fatty acid, terminal fatty alkene, polyol and FAME-based surfactant or polyester or FAEE-based surfactant or polyester.

[0032] In still further preferred embodiments, the fatty acid methyl ester (FAME) or fatty acid ethyl ester (FAEE) is processed into fatty alcohol by reacting FAME or FAEE with hydrogen in the presence of at least 3% by weight of a catalyst selected from the group consisting of CuO, CU2O and a combination of both applied on a carrier selected from the group consisting of AI2O3, ZrC>2, TiC>2 and SiC>2 for at least 12 hours at at least 150 °C under a H2 atmosphere with a pressure of at least 200 bar.

[0033] In preferred embodiments,

[0034] - the reaction time is between 16 to 40 hours and preferably between 24 to 36 hours;

[0035] - the reaction temperature is between 160 to 300 °C, preferably between 175 to 265 °C and more preferably between 190 to 230 °C;

[0036] - the reaction mixture comprises 2 to 8 % and preferably 4 to 6 % by weight of the catalyst; and / or

[0037] - the H2 partial pressure is between 170 to 380 bar and preferably between 250 to 300 bar.

[0038] In other preferred embodiments, the fatty alcohol is purified by rotary evaporation and / or distillation.

[0039] In preferred embodiments, step iia) is conducted.

[0040] Detailed description of the invention

[0041] In the present invention, the inventors surprisingly found a fatty oil composition obtained by cold pressing of dried insect larvae and containing significant amounts of impurities can directly be used in a reaction using alkali metal alkoxide salts such as methoxide or ethoxide. The reaction products are glycerol and fatty acid methyl ester (FAME) or fatty acid ethyl ester (FAEE). This one-step reaction can be up scaled for industrial applications. On the other hand, the proteins remained in the dried larvae can be used in diverse applications, such as products of the food and feed industry.

[0042] In a first aspect, the present invention is directed to a method for preparation, and preferably processing, of fatty acid methyl ester (FAME) or fatty acid ethyl ester (FAEE) comprising: i) obtaining a fatty oil composition by mechanical treatment of dried insects, with the proviso that the treatment does not include a chemical extraction step; iia) reacting the fatty oil composition of step i) in methanol comprising at least 0.5 % by weight of sodium methoxide, potassium methoxide or lithium methoxide for at least 30 minutes at at least 60 °C under N2 atmosphere with a pressure of at least 2.5 bar, in order to obtain the fatty acid methyl ester (FAME), or iib) reacting the fatty oil composition of step i) in ethanol comprising at least 0.5 % by weight of sodium ethoxide, potassium ethoxide or lithium ethoxide for at least 30 minutes at at least 60 °C under N2 atmosphere with a pressure of at least 2.5 bar, in order to obtain the fatty acid ethyl ester (FAEE).

[0043] The term “fatty acid methyl ester”, “FAME” or “biodiesel”, as interchangeably used herein, refers to a compound having between 9 to 31 carbon atoms. Thus, fatty acid methyl esters prepared by the method of the present invention are according to Formula (I):

[0044] Formula (I) wherein R1 is C7 to C29 alkyl or C7 to C29 alkenyl.

[0045] Preferably, the fatty acid methyl ester has between 11 to 21 carbon atoms. In these compounds R1 is C9 to C19 alkyl or alkenyl.

[0046] The term “fatty acid ethyl ester” or “FAEE”, as interchangeably used herein, refers to a compound having between 10 to 32 carbon atoms. Thus, fatty acid methyl esters prepared by the method of the present invention are according to Formula (II):

[0047] Formula (II) wherein R2 is C7 to C29 alkyl or C7 to C29 alkenyl.

[0048] Preferably, the fatty acid ethyl ester has between 12 to 22 carbon atoms. In these compounds R2 is C10 to C20 alkyl or alkenyl.

[0049] In preferred embodiments, the alkenyl groups of R1 and R2 having one, two or three double bonds, more preferably one double bond. The term “fatty oil composition”, as used herein, refers to the liquid fraction after mechanical treatment of insect larvae. In preferred embodiments, the fatty oil composition may comprise at least 50% of fatty acids, mono-, di- and triglycerides. In further embodiments, the fatty oil composition comprises at least 60%, at least 70%, at least 80%, at least 90%, at least 91 %, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% by weight of fatty acids, mono-, di- and triglycerides. Molecules of the fatty oil composition that are not fatty acids, mono-, di- and triglycerides comprise proteins, but may also include steroids, nucleic acids, such as DNA and RNA, phospho-, gluco- and sphingolipids, water and sugars including chitin. Fatty acids are defined as a carboxylic acid with an aliphatic chain, which is either saturated or unsaturated. The fatty acids mainly comprise an unbranched chain of an even number of carbon atoms ranging from 8 to 30.

[0050] Monoglycerides are a class of glycerides which are composed of a molecule of glycerol linked to a fatty acid via an ester bond. As glycerol contains both primary and secondary alcohol groups two different types of monoglycerides may be formed; 1 -monoacylglycerols where the fatty acid is attached to a primary alcohol, or a 2-monoacylglycerols where the fatty acid is attached to the secondary alcohol. A diglyceride, or diacylglycerol (DAG), is a glyceride consisting of two fatty acid chains covalently bound to a glycerol molecule through ester linkages. Two possible forms exist, 1 ,2- diacylglycerols and 1 ,3-diacylglycerols. A triglyceride (TG, triacylglycerol, TAG, or triacylglyceride) is an ester derived from glycerol and three fatty acids.

[0051] The term “mechanical treatment”, as used herein, is directed to the treatment of dried insects, in particular dried insect larvae, and how the fatty oil composition is obtained. This treatment does not involve “chemical treatment” as defined below. Mechanical treatment includes, but is not limited to pressing, in particular cold pressing, centrifugation, rotary filtration, in particular rotary vacuum-drum filtration, clarifying decantation and homogenization. Preferably, the mechanical treatment is cold pressing of the insects using a screw press.

[0052] The term “chemical extraction step”, as used herein, relates to the preparation of the fatty oil composition from the dried insect. A chemical extraction step in this process is excluded. Chemical extraction in the sense of the present invention means the treatment of the dried insects with chemical compounds that support or enhance extraction of fatty acids, mono-, di- and triglycerides from the insect. This includes surfactants or hydrophobic compounds or liquids, including diethylether, petroleum ether or other unipolar solvents. Also included is enzymatic extraction, including the use of proteases and / or lipases, or microbial extraction. Further, the term “chemical extraction step” also includes methods using chemical compounds in combination with other processes, such as using microwaves or ultrasonic waves. Thus, the method of the invention does not include the use of chemical compounds, enzymes, or even whole microorganisms alone or in combination with processes, such as microwave treatment or ultrasonic baths.

[0053] In further embodiments, between steps i) and iia) or iib) the fatty oil composition may be filtered or refined. In more preferred embodiments, non-soluble particles are separated from the fatty oil composition. “Dried”, as used herein, means that the insects have a water content of less than 50%, less than 40%, less than 30%, less than 25%, less than 20%, less than 15%, less than 10%, less than 5% or less than 1 % by weight.

[0054] The term “insect”, as used herein, refers to a specific class of Arthropoda. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body (head, thorax and abdomen), three pairs of jointed legs, compound eyes and one pair of antennae.

[0055] The reaction steps iia) and iib) of the inventive method are directed to the reaction of the fatty oil composition with methanol or ethanol in the presence of alkali metal alkoxide salts such as methoxide or ethoxide. This reaction includes a solvolysis or transesterification of mono-, di- and triglycerides to directly form glycerol and the corresponding fatty acid methyl ester (FAME) or fatty acid ethyl ester (FAEE). Thus, the products of the present method do not only include FAME or FAEE but also include as a side product glycerol.

[0056] The term “methoxide”, as used herein, refers to the anion CH3O-. The term “ethoxide”, as used herein, refers to the anion CH3CH2O-.

[0057] The term “processing”, as used herein, is intended to be understood broadly. This means that this term covers the processing of all components that are part of the inventive method. Further, this means that FAME and FAEE may be further reacted to form fatty alcohols or other compounds as described in more detail below. However, this processing can also refer to the further processing of the dried insects after mechanical treatment. Thus, in preferred embodiments, the inventive methods also include one or more steps resulting in the recovery of the protein fraction from the dried and mechanically treated insects.

[0058] In preferred embodiments, the fatty oil composition has a protein content of at least 0.1 %, at least 0.25%, at least 1 %, at least 3%, at least 5%, at least 7% or at least 10% in relation to the total weight of said composition.

[0059] In other preferred embodiments, the amount of fatty oil composition reacted in step iia) or iib) is at least 10 gram, preferably at least 20 gram and more preferably at least 25 gram. It is noted that the present method can be up scaled for industrial applications, therefore the amount of fatty oil composition reacted in step iia) or iib) may be at least 500 gram, at least 1 kilogram, at least 10 kilogram, at least 50 kilogram or at least 100 kilogram.

[0060] In still further preferred embodiments, the mechanical treatment is pressing and more preferably cold pressing. In more preferred embodiments, the cold pressing is applied using a screw press.

[0061] In preferred embodiments, the alkali metal methoxide is sodium methoxide (CHsNaO).

[0062] In other preferred embodiments, in the reaction of step iia) or iib) - the reaction time is between 20 to 120 minutes and preferably between 30 to 90 minutes and more preferably between 45 to 75 minutes;

[0063] - the reaction temperature is between 65 to 100 °C, preferably between 75 to 95 °C and more preferably between 80 to 90 °C;

[0064] - the methanol comprises 0.25 to 2 % and preferably 0.5 to 1 .5 % by weight of the alkali metal methoxide;

[0065] - the ethanol comprises 0.25 to 2 % and preferably 0.5 to 1.5 % by weight of the alkali metal ethoxide; and / or

[0066] - the N2 partial pressure is between 2 to 10 bar, preferably between 3.5 to 7.5 bar and more preferably between 4 to 5 bar.

[0067] Further, in preferred embodiments, the reaction of step iia) or iib) does not include addition of boron trifluoride (BF3).

[0068] In still further embodiments, the insect

[0069] - was dried at its larva stage; and / or

[0070] - is a holometabolic insect.

[0071] Holometabolic insects show a complete metamorphosis meaning that the insect development includes all four life stages: egg, larva, pupa, and imago (or adult). The larva is a distinct juvenile form before insects undergo metamorphosis into adults. The larva's appearance is generally very different from the adult form (e.g. caterpillars and butterflies) including different unique structures and organs that do not occur in the adult form. Their diet may also be considerably different. The larva used in the method of the present invention may have a high fat content. In some embodiments, the larva comprises at least 60%, at least 70%, at least 80% or at least 90% by weight of fatty acids, mono-, di- and triglycerides.

[0072] The term “holometabolic insects”, as used herein, relates to the following orders: Diptera, Megaloptera, Raphidioptera, Neuroptera, Coleoptera, Strepsiptera, Hymenoptera, Trichoptera, Lepidoptera, Mecoptera, and Siphonaptera.

[0073] In preferred embodiments, the insect isfrom the genus of Diptera, preferably Brachycera and is more preferably Hermetia illucens.

[0074] In other preferred embodiments, the fatty acid methyl ester (FAME) or fatty acid ethyl ester (FAEE) is purified by phase separation and / or distillation. “Phase separation”, as used herein, refers to the transformation of a homogenous system (e.g., dope formulation) into two or more phases. In the present invention, the phase separation may be performed based on the mechanism of vapor induced phase separation (VIPS). The term “distillation”, as used herein, refers to a method for heating a solution comprising FAME, FAEE or a corresponding fatty alcohol till the boiling point thereof and separating the volatile component contained therein.

[0075] In more preferred embodiments, the above-described phase separation is conducted without the need for additives / additional solvents (such as glycerol, n-hexane or petroleum ether). In still other preferred embodiments, the fatty acid methyl ester (FAME) or fatty acid ethyl ester (FAEE) is processed into fatty alcohol, fatty amine, fatty amide, fatty acid carboxylate, fatty methyl ketone, dimer fatty acid, terminal fatty alkene, polyol and FAME based surfactant or polyester or FAEE based surfactant or polyester. The above-described compounds may comprise 8 to 30 carbon atoms and may have a linear structure. Preferably, the functional groups, such as alcohol, amine, amide and carboxylate groups are terminally located. This processing step of converting the fatty acid methyl ester (FAME) or fatty acid ethyl ester (FAEE) into fatty alcohol, fatty amine, fatty amide, fatty acid carboxylate, fatty methyl ketone, dimer fatty acid, terminal fatty alkene, polyol and FAME based surfactant or polyester or FAEE based surfactant or polyester, in particular fatty alcohol, can be considered as step Hi) of the present method.

[0076] The term “fatty methyl ketone”, as used herein, refers to a compound according to Formula (3),

[0077] O

[0078] R3^ / '^XCH3

[0079] Formula (3), wherein R3 is C7 to C29 alkyl or C7 to C29 alkenyl, preferably, C10 to C20 alkyl or alkenyl.

[0080] The term “terminal fatty alkene”, as used herein, refers to a compound possessing 7 to 29, preferably 10 to 20 carbon atoms in a linear chain, wherein at one end the first two carbon atoms are connected by a double bond.

[0081] In still further preferred embodiments, the fatty acid methyl ester (FAME) or fatty acid ethyl ester (FAEE) is processed into fatty alcohol by reacting FAME or FAEE with hydrogen in the presence of comprising at least 3% by weight of a catalyst selected from the group consisting of CuO, CU2O and a combination of both applied on a carrier selected from the group consisting of AI2O3, ZrC>2, TiC>2 and SiC>2 for at least 12 hours at at least 150 °C under a H2 atmosphere with a pressure of at least 200 bar.

[0082] Thus, the catalysts include CuO on a AI2O3 carrier, CuO on a ZrO2 carrier, CuO on a TO2 carrier and CuO on a SiO2 carrier. Alternatively, the catalysts include CU2O on a AI2O3 carrier, CU2O on a ZrO2 carrier, CU2O on a TO2 carrier and CU2O on a SiO2carrier.

[0083] In preferred embodiments,

[0084] - the reaction time is between 16 to 40 hours and preferably between 24 to 36 hours;

[0085] - the reaction temperature is between 160 to 300 °C, preferably between 175 to 265 °C and more preferably between 190 to 230 °C;

[0086] - the reaction mixture comprises 2 to 8 % and preferably 4 to 6 % by weight of the catalyst; and / or

[0087] - the H2 partial pressure is between 170 to 380 bar and preferably between 250 to 300 bar.

[0088] In other preferred embodiments, the fatty alcohol is purified by rotary evaporation and / or distillation. The term “rotary evaporation”, as used herein, refers to methods that include the use of a rotary evaporator[ (rotavap).

[0089] In preferred embodiments, step iia) is conducted.

[0090] Examples

[0091] I. General Information

[0092] Typically, the experiments for the transesterification step (transesterification of triacylglycerol (TAG) to FAME) were carried out at a temperature range of 85 °C at 4 bar nitrogen pressure either in a 300 mL or in a 9 L autoclave (one-pot reaction vessel). The reaction time was preferably 1 h.

[0093] The method characteristically comprises the use of three main components: the fat / triglyceride as the starting material, methanol as the solvent and sodium methylate as the catalyst. The product is FAME and a side product is glycerol.

[0094] Afterwards, a phase separation may be conducted. The lower phase (glycerol) can be discarded. In case of difficult phase separations, the addition of glycerol and / or heptane may be considered. On larger scale, this solvent addition is usually unnecessary.

[0095] Typically, the subsequent distillation of the obtained crude FAME (upper phase) was carried out at a temperature range of 175-250 °C and a vacuum pressure of 2-12 mbar. Firstly, residual methanol and other volatile “light boilers” (boiling point up to the one of FAME) were removed. Secondly, a mixture of FAME could be distilled off. Thirdly, the sump contains all “high boilers” such as byproducts and impurities from residual protein and DNA.

[0096] Analyses of the obtained FAME were performed by elemental analysis and quantitative GC (with an internal standard).

[0097] Typically, the experiments for the hydrogenation step (hydrogenation of FAME to fatty alcohol) were carried out at a temperature of 210 °C and a hydrogen pressure of 270 bar either in a 300 mL or in a 9 L autoclave (one-pot reaction vessel).

[0098] The method characteristically comprises the use of three main components: distilled FAME, hydrogen and a heterogenous catalyst.

[0099] The following reaction parameters were used for the conducted experiments: the reaction time was 30-40 h, preferably 36 h

[0100] Typically, the copper-based catalysts have to be activated under an atmosphere of hydrogen in the autoclave prior to its use for the hydrogenation. In the present case, the catalysts were typically activated. Analyses were performed by gas chromatography (GC) and measurement of chemical numbers (OH number and iodine number).

[0101] Insect fat / triglyceride was commercially obtained from Hermetia Baruth GmbH (Baruth / Mark, Germany). Dried Hermetia larvae were cold pressed without using chemical additives to obtain the insect lipid / fat / triglyceride / triacylglyceride. The insect lipid was used in its filtered form (Examples 1 , 2 and 3) or directly with no further purification steps (Example 4) for further synthesis. All other chemicals used were purchased from chemical wholesale.

[0102] II. Representative procedures

[0103] Example 1 : Transesterification and FAME distillation (smaller scale)

[0104] Sodium methylate (1 g) was added to a mixture of insect lipid (103 g; filtered) and methanol (24 g) in an autoclave. The reaction vessel was closed and subsequently purged with nitrogen gas (thrice at 5 bar). Under atmospheric pressure (1 bar) and at 60° C, stirring (700 U / min) was applied. The reaction mixture was warmed to 85 °C and the nitrogen pressure was maintained at 4 bar.

[0105] The reaction mixture was stirred under these conditions for 1 h, then cooled to room temperature. Afterwards, the phases were separated and the upper phase was distilled (at 175-225° C, 2-4 mbar). The distillation yielded a liquid sample of FAME (84 g).

[0106] Example 2: Transesterification and FAME distillation (large scale)

[0107] Sodium methylate (40 g) was added to a mixture of insect lipid (4033 g; filtered) and methanol (866 g) in an autoclave. The reaction vessel was closed and subsequently purged with nitrogen gas (thrice at 5 bar). Under atmospheric pressure (1 bar) and at 60° C, stirring (700 U / min) was applied. The reaction mixture was warmed to 85 °C and the nitrogen pressure was maintained at 4 bar.

[0108] The reaction mixture was stirred under these conditions for 1 h, then cooled to room temperature. Afterwards, the phases were separated and the upper phase was distilled (at 200-240° C, 2-11 mbar). The distillation yielded a liquid sample of FAME (3307 g).

[0109] Example 3: Transesterification and FAME distillation with unfiltered insect fat

[0110] Sodium methylate (0.8 g) was added to a mixture of insect lipid (79 g; non-purified) and methanol (19 g) in an autoclave. The reaction vessel was closed and subsequently purged with nitrogen gas (thrice at 5 bar). Under atmospheric pressure (1 bar) and at 60° C, stirring (700 U / min) was applied. The reaction mixture was warmed to 85 °C and the nitrogen pressure was maintained at 4 bar.

[0111] The reaction mixture was stirred under these conditions for 1 h, then cooled to room temperature. Afterwards, glycerol (21 g) and heptane (80 mL) were added, and the phases were separated. The lower phase was extracted once with heptane (40 mL) and the upper phases were combined. The solvent was removed by evaporation and the crude material was distilled (at 130-175° C, 2-7 mbar). The distillation yielded a liquid sample of FAME (72 g).

[0112] Example 4: Transesterification with additional insect protein contamination and FAME distillation

[0113] Sodium methylate (1 .0 g) was added to a mixture of insect lipid (100 g; filtered), insect protein (10 g) and methanol (24 g) in an autoclave. The reaction vessel was closed and subsequently purged with nitrogen gas (thrice at 5 bar). Under atmospheric pressure (1 bar) and at 60° C, stirring (700 U / min) was applied. The reaction mixture was warmed to 85 °C and the nitrogen pressure was maintained at 4 bar.

[0114] The reaction mixture was stirred under these conditions for 1 h, then cooled to room temperature. Afterwards, the phases were separated and the upper phase was distilled (at 150-280° C, 2 mbar). The distillation yielded a liquid sample of FAME (80 g).

[0115] Example 5: Analysis of FAME synthesized in Examples 1-4

[0116] The following Table 1 shows the quantified contents of different fatty acid methyl esters sorted by their chain length as determined by GC (use of a fatty acid methyl ester standard mixture as a reference).

[0117] Table 1

[0118] Table 1 continuation

[0119] Table 1 continuation

[0120] Example 6: Catalyst activation

[0121] The catalyst for the hydrogenation reaction, namely a catalyst comprising CuO, AI2O3 and La2C>3 was placed in an autoclave. The reaction vessel was closed and subsequently purged with nitrogen gas (thrice at 20 bar) and then charged with hydrogen gas. At an initial hydrogen gas pressure of 50 bar, the reaction vessel was heated to 200° C (with a heating rate of 100° C / h).

[0122] Then, the reaction vessel was cooled to room temperature and depressurized to normal pressure (1 bar). Afterwards, the reaction vessel was charged with the starting material via a HPLC pump.

[0123] Example 7: Hydrogenation of FAME and evaporation (smaller scale)

[0124] FAME (100 g) was added to the activated catalyst (5.0 g) in an autoclave. The reaction vessel was subsequently purged with nitrogen gas (once at 20 bar). At an initial hydrogen gas pressure of 50 bar, stirring (700 U / min) was applied. The reaction mixture was warmed to 210 °C and the hydrogen pressure was increased to and maintained at 270 bar.

[0125] The reaction mixture was stirred under these conditions for 36 h, then cooled to room temperature and purged with nitrogen gas (thrice at 20 bar). Afterwards, the catalyst was separated and the filter cake was washed thrice with methanol. The solvent was removed by evaporation (at 60° C, 9 mbar), yielding the mixture of fatty alcohols as a liquid which solidified upon storage (69 g).

[0126] Example 8: Hydrogenation of FAME and evaporation (large scale)

[0127] FAME (3200 g) was added to the activated catalyst (160 g) in an autoclave. The reaction vessel was subsequently purged with nitrogen gas (once at 20 bar). At an initial hydrogen gas pressure of 50 bar, stirring (700 U / min) was applied. The reaction mixture was warmed to 210 °C and the hydrogen pressure was increased to and maintained at 270 bar.

[0128] The reaction mixture was stirred under these conditions for 36 h, then cooled to room temperature and purged with nitrogen gas (thrice at 20 bar). Afterwards, the catalyst was separated and the filter cake was washed thrice with methanol. The solvent was removed by evaporation (at 60° C, 9 mbar), yielding the mixture of fatty alcohols as a liquid which solidified upon storage (2166 g).

[0129] Example 9: Analysis of fatty alcohols synthesized in Examples 7 and 8 The following Table 2 shows the quantified contents of different fatty alcohols sorted by their chain length as determined by GC (use of a fatty alcohol standard mixture as a reference).

[0130] Table 2

[0131] Example 10: Comparison of the composition of fat from different natural sources

[0132] The following Table 3 shows the quantified heteroatom contents of different samples of fat as determined by elemental analysis.

[0133] Table 3

Claims

Claims1. A method for preparation, and preferably processing, of fatty acid methyl ester (FAME) or fatty acid ethyl ester (FAEE) comprising: i) obtaining a fatty oil composition by mechanical treatment of dried insects, with the proviso that the treatment does not include a chemical extraction step; iia) reacting the fatty oil composition of step i) in methanol comprising at least 0.5 % by weight of sodium methoxide, potassium methoxide or lithium methoxide for at least 30 minutes at at least 60 °C under N2 atmosphere with a pressure of at least 2.5 bar, in order to obtain the fatty acid methyl ester (FAME) or iib) reacting the fatty oil composition of step i) in ethanol comprising at least 0.5 % by weight of sodium ethoxide, potassium ethoxide or lithium ethoxide for at least 30 minutes at at least 60 °C under N2 atmosphere with a pressure of at least 2.5 bar, in order to obtain the fatty acid ethyl ester (FAEE).

2. The method according to claim 1 , wherein the fatty oil composition has a protein content of at least 0.1 %, preferably at least 0.25% and more preferably at least 1 % in relation to the total weight of said composition.

3. The method according to claim 1 or 2, wherein the amount of fatty oil composition reacted in step iia) or iib) is at least 10 gram, preferably at least 20 gram and more preferably at least 25 gram.

4. The method according to any one of claims 1 to 3, wherein the mechanical treatment is pressing and more preferably cold pressing.

5. The method according to any one of claims 1 to 4, wherein the alkali metal methoxide is sodium methoxide.

6. The method according to any one of claims 1 to 5, wherein in the reaction of step iia) or iib) the reaction time is between 20 to 120 minutes and preferably between 30 to 90 minutes and more preferably between 45 to 75 minutes; the reaction temperature is between 65 to 100 °C, preferably between 75 to 95 °C and more preferably between 80 to 90 °C;the methanol comprises 0.25 to 2 % and preferably 0.5 to 1 .5 % by weight of the alkali metal methoxide; the ethanol comprises 0.25 to 2 % and preferably 0.5 to 1 .5 % by weight of the alkali metal ethoxide; and / or the N2 partial pressure is between 2 to 10 bar, preferably between 3.5 to 7.5 bar and more preferably between 4 to 5 bar.

7. The method according to any one of claims 1 to 6, wherein the reaction of step iia) or iib) does not include addition of boron trifluoride.

8. The method according to any one of claims 1 to 7, wherein the insect- was dried at its larva stage; and / or- is a holometabolic insect.

9. The method according to any one of claims 1 to 8, wherein the insect is from the genus of Diptera, preferably Brachycera and is more preferably Hermetia illucens.

10. The method according to any one of claims 1 to 9, wherein the fatty acid methyl ester (FAME) or fatty acid ethyl ester (FAEE) is purified by phase separation and / or distillation.

11. The method according to any one of claims 1 to 10, wherein the fatty acid methyl ester (FAME) or fatty acid ethyl ester (FAEE) is processed into fatty alcohol, fatty amine, fatty amide, fatty acid carboxylate, polyol and FAME based surfactant or polyester or FAEE based surfactant or polyester.

12. The method according to claim 11 , wherein the fatty acid methyl ester (FAME) or fatty acid ethyl ester (FAEE) is processed into fatty alcohol by reacting FAME or FAEE with hydrogen in the presence of at least 3% by weight of a catalyst selected from the group consisting of CuO, CU2O and a combination of both applied on a carrier selected from the group consisting of AI2O3, ZrC>2, TiC>2 and SiC>2 for at least 12 hours at at least 150 °C under a H2 atmosphere with a pressure of at least 200 bar.

13. The method according to claim 12, wherein the reaction time is between 16 to 40 hours and preferably between 24 to 36 hours;- the reaction temperature is between 160 to 300 °C, preferably between 175 to 265 °C and more preferably between 190 to 230 °C; the reaction mixture comprises 2 to 8 % and preferably 4 to 6 % by weight of the catalyst; and / or the H2 partial pressure is between 170 to 380 bar and preferably between 250 to 300 bar.

14. The method according to claim 12 or 13, wherein the fatty alcohol is purified by rotary evaporation and / or distillation.

15. The method according to any one of claims 1 to 15, wherein step iia) is conducted.

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